W. Ge, M. E. Davis1, H. C. Hines, and K. M. Irvin
The Ohio State University Department of Animal Sciences
Marker-assisted selection (MAS) may increase rate of genetic gain in farm animal breeding. Identifying useful genetic markers is the first and most critical step in MAS. This study was designed to identify genetic markers in beef cattle. Genomic DNA was isolated from blood samples of purebred Angus beef cattle divergently selected for high or low blood serum IGF-I concentrations. Fragments of DNA in the IGF-I, GH, and GHR genes were amplified using PCR and examined for polymorphism using SSCP, DGGE, and sequencing methods. Nine single nucleotide polymorphisms were identified – one in the promoter region of the IGF-I gene, three in the promoter region of the GH gene, and one in the promoter region and four in exon 10 of the GHR gene. Rapid genotyping methods were developed for determination of genotypes for these markers. A total of 763 calves were genotyped for the IGF-I polymorphism, and 473 calves were genotyped for six other polymorphisms. Statistical analyses are being conducted to test the association of these markers with blood serum IGF-I concentration and growth traits in Angus beef cattle.
1 For more information, contact at: The Ohio State University, 221 Plumb Hall, 2027 Coffey Road, Columbus, OH 43210, 614-292-4984, Fax 614-292-7116, e-mail: davis.28@osu.edu